Lung cancer is the leading cause of malignancy-related mortality because of its high incidence and the lack of effective treatments. Since tobacco usage contributes to 85-90% of its development, tobacco cessation is the most straightforward strategy for reducing lung cancer incidence and mortality. However, because of the addictive nature of nicotine in tobacco, limited progress has been achieved in reducing tobacco usage. An alternative approach is to block or slow down tobacco carcinogen-induced lung cancer development via chemoprevention (Hecht et al., Nat. Rev. Cancer 2009; 9:476-88). Although a number of compounds have been identified as potential chemopreventive agents against lung tumorigenesis in animal models, their moderate in vivo efficacy leaves ample room for improvement and introduces significant challenges for clinical application/evaluation. In addition, there are very limited successes in cancer chemoprevention relative to cancer therapy. Therefore, there is currently an unmet need for additional agents that are useful for treating or preventing cancer.